Study of Variability in Long-term Multiwavelength Optical Lightcurves of Blazar AO 0235+164

Autores
Cellone, Sergio Aldo; Romero, Gustavo Esteban
Año de publicación
2023
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
We present a long-term and intraday variability study of optical multiwaveband (UBVRI) data from the blazar AO 0235+164 collected by various telescopes for ∼44 yr (1975–2019). The blazar was found to be significantly variable over the years in all wave bands with a variation of about 6 mag between its low and active states. The variations in the different wave bands are highly correlated without any time lag. We did not observe any significant trend in color variation with time, but we observed a bluer-when-brighter trend between the B − I color index and the R magnitude. Optical BVR-band spectral energy distributions always show a convex shape. Significant intraday variability was frequently seen in the quasi-simultaneous observations of AO 0235+164 made on 22 nights in the R and V bands by the CASLEO and CAHA telescopes during 1999–2019. We also estimated a central supermassive black hole mass of 7.9 × 10⁷ M☉ by analyzing the broad Mg II emission line in AO 0235 +164ʼs spectrum. We briefly explore the probable physical scenarios responsible for the observed variability.
Instituto Argentino de Radioastronomía
Facultad de Ciencias Astronómicas y Geofísicas
Materia
Ciencias Astronómicas
Galaxies
Active galaxies
BL Lacertae objects
Quasars
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/152611

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oai_identifier_str oai:sedici.unlp.edu.ar:10915/152611
network_acronym_str SEDICI
repository_id_str 1329
network_name_str SEDICI (UNLP)
spelling Study of Variability in Long-term Multiwavelength Optical Lightcurves of Blazar AO 0235+164Cellone, Sergio AldoRomero, Gustavo EstebanCiencias AstronómicasGalaxiesActive galaxiesBL Lacertae objectsQuasarsWe present a long-term and intraday variability study of optical multiwaveband (UBVRI) data from the blazar AO 0235+164 collected by various telescopes for ∼44 yr (1975–2019). The blazar was found to be significantly variable over the years in all wave bands with a variation of about 6 mag between its low and active states. The variations in the different wave bands are highly correlated without any time lag. We did not observe any significant trend in color variation with time, but we observed a bluer-when-brighter trend between the B − I color index and the R magnitude. Optical BVR-band spectral energy distributions always show a convex shape. Significant intraday variability was frequently seen in the quasi-simultaneous observations of AO 0235+164 made on 22 nights in the R and V bands by the CASLEO and CAHA telescopes during 1999–2019. We also estimated a central supermassive black hole mass of 7.9 × 10⁷ M☉ by analyzing the broad Mg II emission line in AO 0235 +164ʼs spectrum. We briefly explore the probable physical scenarios responsible for the observed variability.Instituto Argentino de RadioastronomíaFacultad de Ciencias Astronómicas y Geofísicas2023info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfhttp://sedici.unlp.edu.ar/handle/10915/152611enginfo:eu-repo/semantics/altIdentifier/issn/1538-4365info:eu-repo/semantics/altIdentifier/doi/10.3847/1538-4365/acb059info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by/4.0/Creative Commons Attribution 4.0 International (CC BY 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-09-29T11:39:32Zoai:sedici.unlp.edu.ar:10915/152611Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:39:32.53SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv Study of Variability in Long-term Multiwavelength Optical Lightcurves of Blazar AO 0235+164
title Study of Variability in Long-term Multiwavelength Optical Lightcurves of Blazar AO 0235+164
spellingShingle Study of Variability in Long-term Multiwavelength Optical Lightcurves of Blazar AO 0235+164
Cellone, Sergio Aldo
Ciencias Astronómicas
Galaxies
Active galaxies
BL Lacertae objects
Quasars
title_short Study of Variability in Long-term Multiwavelength Optical Lightcurves of Blazar AO 0235+164
title_full Study of Variability in Long-term Multiwavelength Optical Lightcurves of Blazar AO 0235+164
title_fullStr Study of Variability in Long-term Multiwavelength Optical Lightcurves of Blazar AO 0235+164
title_full_unstemmed Study of Variability in Long-term Multiwavelength Optical Lightcurves of Blazar AO 0235+164
title_sort Study of Variability in Long-term Multiwavelength Optical Lightcurves of Blazar AO 0235+164
dc.creator.none.fl_str_mv Cellone, Sergio Aldo
Romero, Gustavo Esteban
author Cellone, Sergio Aldo
author_facet Cellone, Sergio Aldo
Romero, Gustavo Esteban
author_role author
author2 Romero, Gustavo Esteban
author2_role author
dc.subject.none.fl_str_mv Ciencias Astronómicas
Galaxies
Active galaxies
BL Lacertae objects
Quasars
topic Ciencias Astronómicas
Galaxies
Active galaxies
BL Lacertae objects
Quasars
dc.description.none.fl_txt_mv We present a long-term and intraday variability study of optical multiwaveband (UBVRI) data from the blazar AO 0235+164 collected by various telescopes for ∼44 yr (1975–2019). The blazar was found to be significantly variable over the years in all wave bands with a variation of about 6 mag between its low and active states. The variations in the different wave bands are highly correlated without any time lag. We did not observe any significant trend in color variation with time, but we observed a bluer-when-brighter trend between the B − I color index and the R magnitude. Optical BVR-band spectral energy distributions always show a convex shape. Significant intraday variability was frequently seen in the quasi-simultaneous observations of AO 0235+164 made on 22 nights in the R and V bands by the CASLEO and CAHA telescopes during 1999–2019. We also estimated a central supermassive black hole mass of 7.9 × 10⁷ M☉ by analyzing the broad Mg II emission line in AO 0235 +164ʼs spectrum. We briefly explore the probable physical scenarios responsible for the observed variability.
Instituto Argentino de Radioastronomía
Facultad de Ciencias Astronómicas y Geofísicas
description We present a long-term and intraday variability study of optical multiwaveband (UBVRI) data from the blazar AO 0235+164 collected by various telescopes for ∼44 yr (1975–2019). The blazar was found to be significantly variable over the years in all wave bands with a variation of about 6 mag between its low and active states. The variations in the different wave bands are highly correlated without any time lag. We did not observe any significant trend in color variation with time, but we observed a bluer-when-brighter trend between the B − I color index and the R magnitude. Optical BVR-band spectral energy distributions always show a convex shape. Significant intraday variability was frequently seen in the quasi-simultaneous observations of AO 0235+164 made on 22 nights in the R and V bands by the CASLEO and CAHA telescopes during 1999–2019. We also estimated a central supermassive black hole mass of 7.9 × 10⁷ M☉ by analyzing the broad Mg II emission line in AO 0235 +164ʼs spectrum. We briefly explore the probable physical scenarios responsible for the observed variability.
publishDate 2023
dc.date.none.fl_str_mv 2023
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Articulo
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://sedici.unlp.edu.ar/handle/10915/152611
url http://sedici.unlp.edu.ar/handle/10915/152611
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/issn/1538-4365
info:eu-repo/semantics/altIdentifier/doi/10.3847/1538-4365/acb059
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International (CC BY 4.0)
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International (CC BY 4.0)
dc.format.none.fl_str_mv application/pdf
dc.source.none.fl_str_mv reponame:SEDICI (UNLP)
instname:Universidad Nacional de La Plata
instacron:UNLP
reponame_str SEDICI (UNLP)
collection SEDICI (UNLP)
instname_str Universidad Nacional de La Plata
instacron_str UNLP
institution UNLP
repository.name.fl_str_mv SEDICI (UNLP) - Universidad Nacional de La Plata
repository.mail.fl_str_mv alira@sedici.unlp.edu.ar
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